It is weird, because if you can upload codes, you should be able to get it to send data.To make sure we are in the same page, upload this same above code one more time and right after upload, open Serial Monitor without disconnecting the cable or even touching it at all.Do you get anything after 10 to 15mins?If you do not, make sure that "Both NL & CR" is selected on the left side of the baud rate.On the top part of the window, by the Send button, type "GET / HTTP" and hit enter.Do you get anything now?

Your code looks fine, nothing that would interfere. Just an FYI though, you can't monitor for power outages with the main relay box since the RA will also lose power in that scenario. You can monitor your expansion relay boxes only.